A single column cartridge magazine is a well-known type of cartridge magazine. There are several benefits for this particular cartridge magazine type. It is simple and reliable. The cartridge to be fed into the chamber is initially on the same vertical plane as the chamber, which means that the cartridge does not need to move sideways while feeding into the chamber. The single column magazine is also generally easier and cheaper to manufacture than a double column magazine. The width of a firearm having a double column magazine is greater than a firearm with a single column magazine. In some cases this width is a disadvantage, especially if a narrow receiver and stock is expected. Also the receiver construction is easier to design and manufacture when there is not a wide opening needed for cartridges to be loaded from the double column cartridge magazine. In those cases where extreme strength of the receiver is requested, this single column cartridge magazine allows more material on the lower part of the receiver and thus stiffer construction.
A single column cartridge magazine has a smaller cartridge capacity than a double column cartridge magazine having the same depth. In addition to this feature, a single column cartridge magazine is not preferred in all circumstances. Some users prefer to insert new cartridges to the magazine via ejection opening of the receiver when the bolt is in the open position. In a traditional version of a single column cartridge magazine this is not possible. The user must detach the magazine and load it while it is separated from the firearm. To load the cartridge magazine the user needs to press the rear of the cartridge beneath the retaining lips and push the cartridge rearwards. This is because the retaining lips of the cartridge magazine need to be designed such that a mutual distance between the retaining lips is smaller than the diameter of the cartridge case in order to function correctly. In a single column cartridge magazine the retaining lips of the cartridge magazine set the height of the topmost cartridge in relation to the frame of the cartridge magazine and the receiver of the firearm. When the bolt is moved to the closed position, the face of the bolt takes the topmost cartridge from the cartridge magazine and loads this cartridge into the chamber. So basically to remove the topmost cartridge from the cartridge magazine requires horizontal movement in a feeding direction to be released under the down-pressing contact of the retaining lips.
The single column cartridge magazine sets the cartridges in one column having a virtual vertical centerline, which centerline is also the centerline of the chamber and the barrel. Thus, there is no need for movement of a cartridge sideways during the loading. The cartridge need only be moved vertically from the position defined by the cartridge magazines retaining lips to the chamber. This elevation is normally done by a conically shaped feeding ramp, which is located at the rear end of the chamber. When the topmost cartridge is pushed to the chamber by the bolt, the first contacting end of the cartridge is the bullet and it slides along the feeding ramp and guides the cartridge into the chamber.